tcg-print-server/app.py

from flask import Flask, request, jsonify
import os
import threading
import queue
import pdf2image
from brother_ql.conversion import convert
from brother_ql.backends.helpers import send, status
from brother_ql.raster import BrotherQLRaster
from PIL import Image
import mimetypes
import logging
from logging.handlers import RotatingFileHandler
import time

app = Flask(__name__)

# Set up logging
log_file = 'log.txt'

# Create a rotating file handler for logging
log_handler = RotatingFileHandler(log_file, maxBytes=10*1024*1024, backupCount=5)  # 10MB per log file, keep 5 backups
log_handler.setLevel(logging.DEBUG)
log_formatter = logging.Formatter('%(asctime)s - %(levelname)s - %(message)s')
log_handler.setFormatter(log_formatter)

# Add the log handler to the Flask app's logger
app.logger.addHandler(log_handler)

# Ensure Flask app uses our logger, not its default one
app.logger.setLevel(logging.DEBUG)

# Create a queue to hold the files for processing
file_queue = queue.Queue()
image_queue = queue.Queue()

lock = threading.Lock()

# Directory to save uploaded files (you can modify this path)
UPLOAD_FOLDER = './uploads'
IMAGE_FOLDER = './images'
os.makedirs(UPLOAD_FOLDER, exist_ok=True)
os.makedirs(IMAGE_FOLDER, exist_ok=True)

# Printer configuration
printer_model = "QL-1100"
backend = 'pyusb'
printer = 'usb://0x04f9:0x20a7'

# Convert PDF to image
def convert_pdf_to_images(pdf_path):
    """Converts a PDF to a PIL Image"""
    try:
        images = pdf2image.convert_from_path(pdf_path)
        if images:
            return images
        return None
    except Exception as e:
        app.logger.error(f"Error converting PDF: {str(e)}")
        return None

# Function to print address labels
def print_address_label(image, pdf_path):
    try:
        if 'address' in pdf_path.lower():
            target_width = 1660
            target_height = 1164
            image = image.convert("RGB")
            image = image.resize((target_width, target_height), Image.LANCZOS)
            image = image.rotate(90, expand=True)
        else:
            target_width = 1164
            target_height = 1660
            image = image.convert("RGB")
            image = image.resize((target_width, target_height), Image.LANCZOS)
        
        qlr = BrotherQLRaster(printer_model)
        qlr.exception_on_warning = True

        app.logger.info("Converting image to printer instructions...")
        instructions = convert(
            qlr=qlr,
            images=[image],
            label='102x152',
            threshold=70.0,
            dither=False,
            compress=False,
            red=False,
            dpi_600=False,
            hq=True,
            cut=True
        )

        app.logger.info("Sending to printer...")
        status = send(
            instructions=instructions, 
            printer_identifier=printer, 
            backend_identifier=backend, 
            blocking=True
        )
        app.logger.info(f"Printer status: {status}")
        app.logger.info("Print job sent successfully")
        
    except Exception as e:
        app.logger.error(f"Error during printing: {str(e)}")

def save_images(images, pdf_path):
    uuid = str(int(time.time()))
    for i, image in enumerate(images):
        if 'address' in pdf_path.lower():
            image.save(os.path.join(IMAGE_FOLDER, f"address_label_{uuid}_{i}.png"), "PNG")
        elif 'packing' in pdf_path.lower():
            image.save(os.path.join(IMAGE_FOLDER, f"shipping_label_{uuid}_{i}.png"), "PNG")
        else:
            image.save(os.path.join(IMAGE_FOLDER, f"unknown_{uuid}_{i}.png"), "PNG")
        image_queue.put((image, pdf_path))

# Worker thread that processes files from the queue
def file_worker():
    while True:
        file_path = file_queue.get()
        if file_path is None:  # Shutdown signal
            break
        app.logger.info(f"Processing file: {file_path}")
        images = convert_pdf_to_images(file_path)
        if images:
            save_images(images, file_path)
        else:
            app.logger.error(f"Failed to convert PDF to images: {file_path}")
        file_queue.task_done()

# Printer worker
def printer_worker():
    while True:
        image, path = image_queue.get()
        if image is None:
            break
        with lock:
            print_address_label(image, path)
        image_queue.task_done()

# Variable to track the printer worker thread
printer_worker_thread = None

# Ensure only one printer worker is created
def start_printer_worker():
    global printer_worker_thread
    if printer_worker_thread is None or not printer_worker_thread.is_alive():
        app.logger.info("Starting printer worker thread.")
        printer_worker_thread = threading.Thread(target=printer_worker, daemon=True)
        printer_worker_thread.start()
    else:
        app.logger.info("Printer worker thread already running.")

# Start the file worker thread
threading.Thread(target=file_worker, daemon=True).start()

# Start the printer worker only once
start_printer_worker()

@app.route('/upload', methods=['POST'])
def upload_file():
    # Check if a file is part of the request
    if 'file' not in request.files:
        app.logger.warning('No file part in request')
        return jsonify({'error': 'No file part'}), 400
    
    file = request.files['file']
    
    if file.filename == '':
        app.logger.warning('No selected file')
        return jsonify({'error': 'No selected file'}), 400

    # Check file type (ensure it's a PDF)
    mime_type, _ = mimetypes.guess_type(file.filename)
    if mime_type != 'application/pdf':
        app.logger.warning(f"Invalid file type: {mime_type}. Only PDF files are allowed.")
        return jsonify({'error': 'Only PDF files are allowed'}), 400

    # Save the file to the uploads folder
    file_path = os.path.join(UPLOAD_FOLDER, file.filename)
    file.save(file_path)
    app.logger.info(f"File {file.filename} uploaded and saved to {file_path}")

    # Add the file path to the queue for processing
    file_queue.put(file_path)

    return jsonify({'message': f'File {file.filename} uploaded and queued for processing'}), 200

if __name__ == '__main__':
    app.run(debug=True)